1. Field of the Invention
The present invention relates to a liquid crystal display apparatus driven by electric fields parallel to a base plate and a color filter for use in the liquid crystal display apparatus.
2. Description of the Related Art
As described in some detail later with reference to FIG. 2, conventional color liquid crystal display apparatuses of, for example, twisted nematic TN (twisted nematic) mode and IPS (in-plain switching) mode (lateral electric field method) normally employ glass fibers or plastic beads as a spacer between a color filter-side base plate and an electrode base plate provided with thin film transistors (TFTs) and a plurality of scan electrodes, in order to maintain the thickness of the liquid crystal layer (cell gap). The spacer such as a plurality of plastic beads is provided by spraying, so that the arrangement of individual spacer elements is uncontrollable, thereby causing problems of deterioration of the display quality of a liquid crystal display device due to light scattering by the spacer elements present on pixels.
Liquid crystal display devices employing sprayed spacer elements, such as plastic beads, also have the following further drawbacks. Since the spacer elements have spherical or rod-like shapes, the spacer elements form point-like or line or like contacts during the pressing of an assembly of base plates into a cell and, therefore, may well break an alignment layer or a transparent electrode in the device, possibly resulting in a display defect. Breakage of an alignment layer or a transparent electrode will also contaminate the liquid crystal and result in a voltage decrease.
Furthermore, a step of uniformly spraying spacer elements is required, or high-precision control of particle size distribution of the spacer elements is required. Thus, it is difficult to provide a liquid crystal display device having a stable display quality by a simple method.
Particularly in IPS mode liquid crystal display apparatuses, there is a need to maintain a cell gap with an increased consistency, thereby requiring an increased number of spacer spraying steps. The IPS mode liquid crystal display apparatuses also suffer more remarkably from the aforementioned problems in that for example, due to its material, the alignment layer may be fragile and conspicuous light scatter by the spacer may occur due to the increased back light intensity.
To solve these problems, JP-A- 63-82405, JP-A-04-93924, and JP-A-07-318950 propose a spacer structure wherein two or three colored layers are laminated. However, in TN-type liquid crystal display apparatuses, in order to prevent a short circuit between transparent electrodes in a portion where the spacer contacts a counter base plate and electrodes in the counter base plate, there is a need to form an insulating film in an upper portion of the counter base plate or the spacer or a need to restrict the position where the spacer is formed or the size of the spacer, thereby making production of a liquid crystal display apparatus difficult.
Accordingly, the present invention seeks to provide a color liquid crystal display apparatus that is easy to produce and excellent in display quality with a high contrast and a wide visual field angle.
Thus, the present invention provides a liquid crystal display apparatus comprising:
a color filter base plate having a transparent substrate, a black matrix and a colored film of three primary colors provided on the transparent substrate,
an electrode-carrying base plate provided with electrodes for applying an electric field parallel to the color filter,
and a liquid crystal disposed therebetween,
wherein a spacer is formed on the black matrix by patterning a resin.